Quasi-elastic lineshapes for atoms and simple molecules undergoing jump rotation on surfaces

We apply an analytic model for discrete jump rotation of a species moving around a circle, to quasi-elastic scattering from single crystal surfaces. Results for several molecule-like geometries are presented and the subsequent form of the intermediate scattering function is identified. These functions give clear signatures, enabling different forms of jump rotation to be distinguished. A simple data reduction is discussed and we show how the true ISF will appear within this simplification.